Performance evaluation of an integrated redesigned coal fired power plant with CO2 capture by calcium looping process

Coal feed power plant (CFPP) contributes to a huge fraction of CO2 emitted to the atmosphere in China. The Calcium Looping (CaL) technology may be the most promising and appropriate for post-combustion CO2 capture from CFPP. Two integration schemes, baseline case and redesigned case, which integrate CaL process into CFPP for CO2 capture, are presented in this manuscript aimed to reduce not only capture cost but efficiency penalty. The thermodynamic performances of integration schemes are investigated, and the heat transfer areas of main exchangers are also compared. The sensitivity analysis is conducted to explore the impacts of compression efficiency as well as turbine efficiency on redesigned case. The results show that redesigned case has a drop of 26.0% in exchangers' total area as comparing to baseline case. The redesigned case can reclaim 52.0 MW more waste heat and output 21.1 MW more net electric power than baseline case. The overall thermal efficiency of redesigned case is 39.02% at 3.5 of Ca:C molar ratio, and corresponding efficiency penalty arising from CO2 capture is 4.87% which is lower by almost 1.0 percentage point than baseline case. The efficiency penalty can also be dropped as increasing compression efficiency and turbine efficiency. A minimum efficiency penalty of 3.69% for the CaL process integration into a CFPP may be achieved if turbines efficiencies are increased by 2% and compressor efficiencies are further increased to 92% under ideal operation conditions.